An electric hybrid vehicle includes an internal combustion engine and one or more electric motor/generators. Some hybrid vehicles utilize one or more motor/generators to provide driving torque in an electric-only operating mode or in combination with the engine, such as an electrically-variable operating mode. The motor/generators may also be used to start the engine from a cold start, from an auto-stop (idle, engine off), or when transitioning from the electric-only mode to the electrically-variable mode
A typical (non-hybrid) accessory drive system transfers driving forces from the engine to automotive accessories via a flexible drive belt wrapped around pulleys on the engine and the accessories. The accessories typically include an alternator. For hybrid powertrains, belt-alternator-starter (BAS) systems employ a combined starter and alternator motor/generator mounted with respect to other components of the accessory drive system, such as a pump, an air conditioner, or other accessories. The BAS system motor/generator is typically mounted and packaged in the same way as a traditional alternator and drives the accessory and engine components via a belt and pulley system.